Question

The cell potential for the following galvanic cell is 1.15 V. The standard cell potential is 1.16 V. If [Au3+]=0.4M, what is the concentration of Cu2+ ? 3Cu+2Au3+→3Cu2++2Au 1.18M 4.12M 1.23M 1.65M 3Cu+2Au3+→3Cu2++2Au \#6 What is conc of Cu2+ 1.15=1.16−60.0692​log0.5[cu2+]3​​

Answer 1

To determine the concentration of Cu2+ in a galvanic cell reaction involving Cu and Au3+, the Nernst equation is used, incorporating the given cell potential, standard cell potential, and the concentration of Au3+. The number of electrons transferred in the reaction is 6. The concentration of Cu2+ is calculated through the antilog of the rearranged Nernst equation.

Step-by-step explanation:

To calculate the concentration of Cu2+ in the given galvanic cell reaction (3Cu + 2Au3+ → 3Cu2+ + 2Au), the Nernst equation is used. The equation relates the cell potential (Ecell) to the standard cell potential (E°cell) and the reaction quotient (Q).

Using the Nernst equation:

Ecell = E°cell - (0.0592/n) × log(Q)

Given values are:

• Ecell = 1.15 V
• E°cell = 1.16 V
• [Au3+] = 0.4 M

The number of electrons transferred in the reaction (n) is 6, as there are 3 moles of Cu oxidized (each losing 2 electrons) and 2 moles of Au3+ reduced (each gaining 3 electrons).

By rearranging the Nernst equation and solving for the concentration of Cu2+, we get:

- = -(0.0592/6) × log(Q)

1.15V - 1.16V = -(0.0592/6) × log([Cu2+]3/0.42)

Rearranging gives the concentration of Cu2+ required to satisfy the above equation. By using the antilogarithm, we can find out the exact concentration of Cu2+.